Semi-structured data is data that lacks a rigid structure and that does not conform directly to a data model, but that has tags, metadata, or elements that describe the data.
Examples of semi-structured data are JSON or XML files.
Semi-structured data often contains enough information that it can be relatively easily converted into structured data.
JSON data embedded inside of a string, is an example of semi-structured data. The string contains all the information required to understand the structure of the data, but is still for the moment just a string — it hasn’t been structured yet.
| data | |
|---|---|
| Record 1 | ”{‘id’: 1, ‘name’: ‘Mary X’}“ |
| Record 2 | ”{‘id’: 2, ‘name’: ‘John D’}” |
It is often relatively straightforward to convert semi-structured data into structured data. Converting semi-structured data into structured data is often done during the Data Transformation stage in an ETL or ELT process.